Current medical practice often relies upon laser energy for various surgical operations. Laser light is capable of cutting, ablating and cauterizing tissue as well as coagulating blood.
Yttrium Aluminum Garnet (YAG) is a host crystal whose dopant-derived lasers emit primarily in the infrared, and are widely used for a variety of surgical applications. Erbium-doped YAG (Er:YAG) laser emission, at a wavelength 2.94 .mu.m, is strongly absorbed by water and thus particularly effective for cutting tissue. When used for tissue surgery, these lasers are typically operated in a pulsed mode, and their rate of cutting is commonly controlled by adjusting the optical energy of the pulses. Unfortunately, increasing the pulse energy to provide more aggressive cutting can result in microfracturing of hard tissue and excessive heating in healthy, outlying soft tissue. Additionally, the lasers themselves may experience instabilities caused by transient heating of the YAG crystal from high pump powers, possibly even decreasing their cutting efficiency.
Thus, there is a clear need in the surgical laser art for a laser which increases cutting efficacy without the detrimental effects associated with high pulse energies.